Apparatus for freezing liquids



Aug. 26, 1947. w. w. MAYNE ErAl. 2,426,368

APPARATUS FOR FREEZING LIQUIDS Filed Dec. 27, 1943 WZLTEQ WMA Y/VE,

ENNETH A. Mae/ H) INVENTORS.

Patented Aug. 26, 1947 2,426,358

APPARATUS FOR FREEZING LIQUIDS Walter W. Mayne and Kenneth A. Murphy,Pasadena, Califl, assignors, by mesne assignments, to Pre-Pak FreezerCorporation, Los Angeles, Calif., a corporation of CaliforniaApplication December 27, 1943, Serial No. 515,860

2 Claims. 1

Our invention relates to apparatus for freezing heterogeneous mixturesand has particular reference to apparatus for quick freezing fruit andvegetable juices such as, for example, orang juice. 5 It isadditionallyan object of our invention It has been found that greatsaving in transto provide an apparatus for quick freezing liquidportation costs and great improvement in the heterogeneous mixtureswhich includes a means facility with which fruit and vegetable juicesmay for rapidly refrigerating liquids in bulk to a point be dispensedcan be obtained by extracting the such that a relatively thick paste isproduced. juice from the fruits and vegetables and freezing It is alsoan object of our invention to provide them before they are transportedto the point of an apparatus of the character set forth in theconsumption. In order to preserve all of the preceding paragraph whichincludes a means for food values and vitamins and to prevent undulyproducing a continuous flow of the juice in both rapid spoiling uponthawing, it is essential that the liquid and paste form through therefrigeratthe juices be frozen as rapidly as possible. This ing chamber.process has come to be known as quick freezing. It is additionally anobject of our invention to Prior to our invention it was the practice toprovide an apparatus of the Character S t forth quick freeze the juiceof fruits and vegetables by hereinbefore which includes a means forconfilling metal containers with the extracted juice tinuouslymaintaining a partial vacuum within and then rapidly refrigerating themetal conthe space in which the juices are refrigerated. tainers. Thisprocess has a number of disad- Other objects and advantages of ourinvention vantages, not the least of which is the requirewill beapparent from a study of the following ment; that the containers used berelatively small specifications, read in connection with the acin orderto obtain a suficiently rapid freezing companying drawings, wherein: ofthe entire contents of the container. Further- 2., Fig. 1 is adiagrammatic elevational view with more, since-the juices are introducedinto the parts shown in section and illustrating one form containers inliquid form, it is desirable that the of apparatus which is particularlyadapted to containers be made of metal since the thermal the practice ofour invention; and conductivity of other container materials is so Fig.2 is a View similar to Fig. 1 but illustrating low as to make itimpractical to obtain a sufila modified form of apparatus particularlyadaptciently rapid freezing with paper, cardboard or ed to the practiceof an improved form of our plastic containers. In war time when suppliesof invention. iron and tin are used exclusively in the produc- As beforestated, it is essential in the quick tion of munition and ordnance, itis impossible freezing of vegetable and fruit juices that the to obtainan adequate supply of cans for use in heat of the liquid and the latentheat of solidithe above mentioned processes. fication be removed sorapidly as to prevent the It is, therefore, an object of our inventionto formation f a ge c ystals and the destruction provide apparatus forquick freezing liquid heteroof the individual cells of the pulp which isalways geneous mixtures such as fruit and vegetable carried by suchjuices. According to the method juices which overcomes the abovementioned (115- of our invention this is accomplished byintroducadvantages by making it practical to use nong e fruit or e b e je o Other liquid metallic containers, heterogeneous mixture into a verylow tempera- It is also an object of our invention to provide turerefrigerating chamber and moving the liquid for quick freezing fruit andvegetable juices by through that chamber continuously at such apreliminarily rapidly refrigerating the juice in rate that it will bedischarged from the chamber bulk to a temperature such that there isproin the form of a heavy P duced a thick paste substantially free fromoc- The paste form of the refrigerated liquid results eluded air, thepaste then being placed in nonfrom the fact that a part of theconstituents of metallic containers and refrigerated sufficiently the qd freeze at a temperature w at to complet th freezing f the i fre juichigher than that required to freeze all of the conwhereby subsequentoxidation of the juice cont t The paste is then placed in Suitable tentis maintained at a minimum. containers, preferably made of cardboard orother It is a still further object of our invention to non-metallicmaterial. The containers are provide apparatus for freezing of thecharacter sealed and placed within a refrigerated storage set forth inthe preceding paragraph in which room, the temperature of which ismaintained the entire process is carried out within an enclosure whichis substantially free of air to thereby eliminate the oxidation of theoxidizable elements of the juice.

sufficiently low to accomplish the final freezin and hardening of thefrozen juices in a relatively short time.

With this method it is possible to use containers of shapes other thanthe conventional cylindrical shape. The juices may, for example, bepacked in rectangular paper cartons, thus effecting not only a materialsaving in cost as regards the container used, but also effecting aconsiderable saving in transportation charges resulting from thereduction in weight effected by substituting a paper or cardboardcontainer for the metal can and resulting also from the fact that therectangular packages may be packed side by side without the waste ofspace which is attendant upon the side by side placing of cylindricalcontainers.

In the freezing of certain vegetable and fruit juices and notably thecitrus juices such as orange, lemon and grapefruit juices, it is foundthat the time between the extraction of the juice and the freezing ofthe juice must be maintained as short as possible if the juice is incontact with the air because during the contact of the juice with theair certain elements of the juice oxidize with great rapidity resultingin a partial destruction of the vitamin content and the development ofdistasteful terebinthinate odors and flavors.

We have found that even though the freezing of the juice be accomplishedin a relatively short time, it is necessary to prevent the mixing .ofair with the juices during the freezing process for the reason that anyair which is mixed with the juices during the freezing process willresult in oxidation of the juice during the time the frozen juice is instorage. Accordingly any agitation of the juice during freezing must beso controlled as to prevent the whipping into the juice of any air. Weprefer to prevent the inclusion of air into the frozen juice bypreventing any whipping action and by operating any agitators or setscrews at a speed sufiiciently low to insure that no air will be whippedinto the juice.

The diiliculty of oxidizing certain of the juice elements may also beavoided according to our invention by introducing the juice into thefreezing chamber immediately after the juice is extracted from the fruitand by maintaining the freezing chamber under vacuum so that a verylarge percentage of the air is removed from the chamber and the freezingprocess takes place in a rarefied atmosphere providing little or nooxygen to oxidize the oxidizable elements of the juice. Alternatively,the process may be carried out in an inert atmosphere of nitrogen, neon,argon or the like.

We have shown in Fig. 1 an apparatus which is particularly adapted tothe practice of our invention. The apparatus comprises a tubularfreezing chamber I which is surrounded by a concentric jacket 2 definingan interior annular space 3. Within the space 3 there is circulated are-= frigerant as by means of an inlet pipe 4 and a discharge pipe 5.The space 3 may, if desired, constitute the evaporator of a conventionalrefrigerating system in which case liquid refrigerant such as liquidammonia, Freon or sulphur dioxide is introduced into the inlet 4 and thegaseous refrigerant resulting from the vaporization of the liquidrefrigerant is returned to the compressor through the discharge line 5which is connected to the suction side of the refrigerating compressor.Alternatively, there may be circulated through the space 3 by means ofthe connections l and. 5 a refrigerated liquid such as alcohol or acalcium chloride solution.

The refrigerator comprising the tubular member I and outer jacket 2 andindicated in Fig. 1 generally by the reference character 6 is preferablysupported in a sloping position as shown in Fig. 1 as by means 01supports I and 8. Liquid to be frozen is introduced into the lower endof the chamber I through a conduit or pipe 9, the same being preferablyconnected to the discharge of a pump I0 shown as comprising a gear pump.The inlet II of the pump comprises a conduit which is connected to thecollector basins of the juice extracting apparatus used to extract thejuice of the particular fruit or vegetable being treated.

The pump I0 may comprise any suitable type of pump and need only operateto insure an adequate supply of liquid into the freezing chamber I, a.back pressure on the pump Ill of from five to ten pounds per squareinch is usually sufficient.

The freezing chamber I is extended upwardly beyond the closed end I2 ofthe refrigerating jacket 2 and is provided at its outer end with anopening I2 in the under side communicating with a funnel or dischargehopper I4 which is preferably placed above a belt conveyor or table l5upon which cartons or containers I6 may be placed in a position toreceive the material discharged from the upper end of the refrigeratingchamber I.

In order to insure a continuous flow of the material through the chamberI and to provide a scraping action along the inside surfaces of thechamber I to prevent the material from freezing up permanently and hard,we place within the chamber I a screw or Archimedes spiral H whichcomprises a drive shaft I8 and a helically wound vane I9 substantiallyfilling the chamber I. We have found that a clearance between the outersurface of the vane l9 and the inner surface of the chamber 1 of 0.010of an inch is suitable for the refrigeration of orange juice.

The shaft I8 is journaled for rotation as by means of a bearing block 20inserted in the end of the chamber I and as by means of an outboardbearing 2| mounted upon a suitable supporting post 22. An electric motor23 or other suitable power means may be used to rotate the screw I! asby means of a belt 24 and pulleys 25 and 26.

The following description of the method and the functioning of the abovedescribed apparatus is made with reference to the freezing of orangejuice, it being understood that slight changes in temperatures andoperating speeds will be required in the treatment of otherheterogeneous mixtures. The orange juice may be introduced into thefreezing chamber I at normal room temperature or, if desired, it may bepro-cooled to a temperature approximately 35 F If a refrigeranttemperature within the space 3 of approximately 10 F. is maintained, athick paste having a temperature of about 25 F. may be dischargedthrough the hopper I 4 by providing the screw IT with a four inch leadand rotating it at a speed of approximately 15 R. P. M. Otherrefrigerating temperatures and other screw pitches will, of course,require a. somewhat different speed of rotation of the screw in order toobtain a discharge of the juice from the machine at the desiredtemperature of about 25 F. In every case, however, the speed of thescrew [1 should be maintained at a sumciently low value to preventwhipping air into the juice to thereby reduce to a minimum the oxidationof the oxidizable elements of the juice.

As soon as the container I6 is filled with the quickly frozen juice inthe paste form, the same is sealed and immediately placed in a hardeningroom in which a temperature of from zero to minus 10'' F. is maintained.Storage at such temperature from four to twenty four hours will resultin a complete hardening of the material, the time required dependingupon the size of the container used and the amount and effectiveness ofthe air circulation within the hardening room.

In order to reduce to a minimum the oxidation of the juice during thefreezing operation, we may employ a modified form of apparatusconstructed along the lines illustrated in Fig 2. The apparatus shown inFig. 2 is identical with that shown in Fig. 1 with the exception of themechanism used in the discharge end of the chamber I. It will be noticedthat the chamber I is arranged to discharge into an enclosure defined bya housing 21. The shaft I8 is extended through an end wall 28 of thehousing 21 and an air-tight seal is provided between the housing 21 andthe shaft l8 as by means of a seal or gland 29.

From the upper side of the housing 21 there is extended an exhaust line30 which is connected to the suction side of a vacuum pump 3|. This pumpserves to continually remove from the housing 21 and from the interiorof the chamber I air that may be present or be introduced with the juiceas it is introduced into the lower end of the chamber. The lower part ofthe housing 21 is preferably made funnel-shaped as shown at 32 andconnected as by means of a conduit 33 to a discharge pump 34 whichserves to remove the juice in its paste form from the funnel or hopper32 and provide a seal preventing the influx of air into the chamber 21through the aperture serving as the discharge for the frozen juices. Thedischarge side of the pump 34 may be connected as by means of a conduit35 to any suitable type of apparatus which may be used to fillcontainers such as the container l6.

From the foregoing it will be observed that we have provided for novelquick freezing liquid heterogeneous mixtures, particularly fruit andvegetable juices and that our invention permits a more economicaltreatment of the liquids to be frozen than is possible with existingapparatus.

It will be further noted that by using our invention packaging of thefrozen commodity in non-metallic containers is permitted. The apparatuswhich we have shown is distinguished by its simplicity and by theprovision of the screw H, as a means for mechanically moving the liquidsthrough the freezing chamber as the freezing process continues, to avoidnecessity of using high pressure pumps and to-absolutely.

prevent the freezing up of the machine due to the liquid sticking to thewalls of the freezing chamber.

While we have shown and described the preferred embodiment of ourinvention, we do not desire to be limited to any of the details ofconstruction shown or described herein, except as defined in theappended claims.

We claim:

1. In an apparatus for rapidly freezing a liquid heterogeneous mixture,the combination of: an elongated freezing chamber; means forrefrigerating said freezing chamber to a temperature substantially belowthe freezing points of the constituents'of said mixture; means forintroducing liquids to be frozen into one end of said chamber; means.for moving said liquids through said chamber at a rate adjusted todischarge said liquids from the other end of said chamber at atemperature below the freezing point of a part of the constituents ofsaid mixture and above "the freezing point of the remainder of saidconstituents; and means for exhausting the interior of said chamber tomaintain a pressure therein substantially less than atmospheric.v

2. In an apparatus for rapidly freezing a liquid heterogeneous mixture,the combination of: an elongated tubular freezing chamber; arefrigerating jacket surrounding said chambe means for supplyingrefrigerant to said jacket at a temperature substantially below thefreezing points of the constituents of said mixture; means forintroducing said mixture into one end of said chamber; screw meansmounted for rotation in said chamber to advance said liquids from oneend to the other thereof; means for rotating said screw means at a speedadjusted to discharge said liquid from the other end of said chamber ata temperature such that said liquid is in a paste-like form; a closedreceivingchamber communicating with the other end of said freezingchamber; means for exhausting said receiving chamber and said freezingchamber to maintain therein a pressure substantially less thanatmospheric; and pump means communicating with said receiving chamberfor withdrawing therefrom material received therein from said freezingchamber.

WALTER W. MAYNE. KENNETH A. MURPHY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Baker Nov. 17,

